IN THE SUPREME COURT OF IOWA

No. 20–1290

Submitted September 15, 2022—Filed December 16, 2022

NATIONWIDE MUTUAL INSURANCE CO.,

Appellant,

vs.

POLK COUNTY BOARD OF REVIEW,

Appellee.

On review from the Iowa Court of Appeals.

Appeal from the Iowa District Court for Polk County, Paul D. Scott, Judge.

Property owner Nationwide Mutual Insurance Co. appeals its property tax 

assessment by the Polk County Board of Review. DECISION OF THE COURT 

OF APPEALS VACATED; DISTRICT COURT JUDGMENT AFFIRMED.

McDermott, J., delivered the opinion of the court, in which all participating 

justices joined. May, J., took no part in the consideration or decision of the case.

Sean P. Moore (argued) of Brown, Winick, Graves, Gross and Baskerville, 

P.L.C., Des Moines, for appellant.

John P. Sarcone, Polk County Attorney, and Mark Taylor (argued) and 

Jason Wittgraf, Assistant Polk County Attorneys, for appellee.
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McDERMOTT, Justice.

This case presents a challenge to a county assessor’s valuation for tax 

purposes of two large corporate office buildings in downtown Des Moines. The 

assessor set the value of the two buildings at $87,050,000 and $44,910,000, 

which the properties’ owner, Nationwide Mutual Insurance Co. (Nationwide), 

protested to the Polk County Board of Review (Board). The Board upheld the 

county assessor’s valuation, and Nationwide appealed to the district court. 

Nationwide and the Board each called two appraisers as expert witnesses. The

district court found the Board’s experts more reliable than Nationwide’s and 

affirmed the assessment. Nationwide then appealed to this court, and we 

transferred the case to the court of appeals. The court of appeals reversed the 

district court’s determination about the relative reliability of the expert testimony

and reduced the assessments. We granted the Board’s application seeking 

further review.

When valuing real property for tax assessments, the law strives for fairness 

and uniformity, operating on the notion that similar properties within a given 

tax classification should be taxed similarly. Because courts reviewing challenges 

to valuations usually lack technical expertise in appraising commercial real 

estate, these types of cases often hinge on a factfinder’s judgment about 

conflicting expert witness testimony. And so it goes in this case.

The question before us centers on whether the Board’s expert appraisers 

grounded their opinions in a flawed appraisal method that didn’t rely enough on 
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sales of similar properties and, thus, whether the district court erred by relying 

on these experts when it affirmed the assessor’s valuation.

I.

The two office buildings at issue—neighboring each other at 1100 Locust 

Street and 1200 Locust Street—have slightly different histories. The building at 

1100 Locust was, in 2002, among the first constructed in what’s known as 

downtown Des Moines’s Western Gateway area. In 2006, Nationwide and the 

City of Des Moines (City) agreed to an expansion project as part of an “urban 

renewal” development agreement. Under this agreement, Nationwide would 

expand its building at 1100 Locust and construct another smaller office building 

at 1200 Locust. In exchange, the City would provide Nationwide about $28 

million in economic incentives to help finance the project. Nationwide further 

agreed that the minimum property values for tax assessment purposes over the 

next ten years—starting from when the construction projects concluded in 

2008—would not fall below $78.5 million for 1100 Locust and $36 million for 

1200 Locust. The protested assessments at issue are for tax years 2017 and 

2018, and thus within the agreement’s ten-year period.

The properties are described with a series of compound adjectives: singletenant, built-to-suit, owner-occupied, corporate headquarters. The building at 

1100 Locust rises seven stories with a gross building area of almost 800,000 

square feet, while 1200 Locust stands five stories with a gross building area of 

almost 372,000 square feet. Nationwide has continued to invest in these 

properties, partially remodeling both buildings between 2011 and 2016.
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The county assessor is generally tasked with valuing the real property in 

a county for tax assessment purposes. For tax years 2017 and 2018, the Polk 

County Assessor increased the valuations of both properties, from $80.23 million 

to $87.05 million for 1100 Locust, and from $41.39 million to $44.91 million for 

1200 Locust. An employee from the Polk County Assessor’s Office testified that 

an initial assessment is typically determined using a mass appraisal technique,

such as a large study of the sales of commercial-class properties, and then 

applying a uniform percentage change for properties within that class. An 

individualized property valuation is prepared only if a property owner files a 

protest.

And that’s what happened here. To arrive at the 2017 valuation, the Polk 

County Assessor took the 2015 property tax valuations for all commercial-class

properties in Des Moines’s central business district (such as 1100 Locust and 

1200 Locust) and added 8.5%. When Nationwide filed its protest, the assessor 

performed an individualized “cost” analysis on both properties using a state 

manual that estimates construction costs if the building were to be constructed 

anew. After deducting estimated physical depreciation based on the buildings’

ages, the assessor arrived at a depreciated value. Because the depreciated value 

exceeded the assessor’s earlier valuation, the Board—the body that adjudicates

property owner protests (and now the defendant in this case)—determined that 

no adjustment to the original tax assessment was warranted and thus denied 

Nationwide’s protest.
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Nationwide filed a petition for judicial review with the district court. In the 

district court, Nationwide and the Board each presented testimony from two 

expert witnesses who had conducted valuations of the properties: for the Board, 

appraisers Mark Kenney and Russ Manternach; for Nationwide, appraisers Don 

Vaske and Tom Scaletty. Each expert analyzed the properties using the three 

valuation methods commonly used to value real property: the “cost” approach, 

which considers the cost of reproducing the property anew minus depreciation;

the “income” approach, which considers the income-producing capacity of the 

property; and the “comparable-sales” (or simply “sales”) approach, which 

compares the property to other properties with similar characteristics that have 

recently sold. 

But each expert emphasized different approaches—and as to the sales 

approach in particular, different properties for comparison—in arriving at a 

“reconciled” value for each property. To give a flavor of the different points of 

emphasis, Kenney (retained by the Board) provided a single combined appraisal 

that Nationwide’s lawyer worked to unpack into its component parts on crossexamination. Kenney gave less weight to the comparable-sales approach because 

he found suitable comparison properties lacking in Des Moines or sufficiently 

similar markets. Kenney also found the income approach ill-fitting.

Manternach (the Board’s other expert) gave the least weight to the cost 

approach because, in his view, the amount of accrued depreciation skewed the 

valuation too much. In his comparable-sales analysis, Manternach used local 

properties, but couldn’t find suitable single-tenant properties. Manternach 
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testified that adjusting a sale of an owner-occupied single-tenant building in a 

larger metropolitan area wouldn’t provide a sufficiently objective comparison.

Vaske (retained by Nationwide) testified that in his view the comparablesales approach offered the most reliable method. He analyzed two properties in 

Des Moines, one in suburban Kansas City, and one in St. Paul. But Vaske had 

to make considerable adjustments in analyzing his proposed comparable 

properties for building age (they weren’t as new as Nationwide’s) and—most 

particularly—size, since two of his comparable properties had square footages of 

only 225,654 and 102,242, while the Nationwide properties are 798,696 and 

371,920.

Scaletty (Nationwide’s other expert) analyzed but assigned no weight to the 

cost approach, instead assigning a 60/40 split to the sales and income 

approaches in his analysis. The local properties that he viewed as comparable 

sales were not owner-occupied, single-tenant buildings. Scaletty’s calculations 

also made the largest adjustment to the gross square footage available for actual 

business use, reducing 1100 Locust’s 798,696 gross square footage by 15%, 

down to 669,565 square feet.

As the table below shows, the experts’ valuations, including their 

reconciled final valuations, varied widely:
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The district court acknowledged that Iowa law requires that county 

assessors first seek to use a comparable-sales approach in setting a valuation, 

and that other approaches should be used only when market value cannot be 

readily determined using the comparable-sales approach. Iowa Code 

§ 441.21(1)(b)(1) (2018). The district court noted that all four expert appraisers 

incorporated the three traditional approaches in arriving at their reconciled 

valuation numbers. 

Although the district court found Nationwide’s experts credible, it found 

the Board’s experts more reliable. The district court thus gave greater weight to 

the Board’s expert valuations, which more closely tracked the county assessor’s

valuation. In its analysis, the district court discounted the testimony of

Nationwide’s associate vice president of corporate real estate, who contended 

that 1100 Locust should not be considered a “corporate headquarters” building. 

While perhaps technically accurate given that Nationwide’s national 

1100 Locust (assessed at $87,050,000)

Board of Review Nationwide

Manternach Kenney Vaske Scaletty

Cost approach $86,100,000 $99,000,000 $54,385,000 $39,470,000

Sales approach $81,300,000 $107,000,000 $48,237,000 $39,390,000

Income approach $82,100,000 $80,000,000 $48,117,000 $39,550,000

Reconciled valuation $82,100,000 $94,000,000 $49,000,000 $39,450,000

1200 Locust (assessed at $44,910,000)

Board of Review Nationwide

Manternach Kenney Vaske Scaletty

Cost approach $44,000,000 $41,000,000 $26,650,000 $23,440,000

Sales approach $42,800,000 $63,000,000 $26,034,000 $22,640,000

Income approach $42,900,000 $55,000,000 $25,134,000 $24,240,000

Reconciled valuation $43,000,000 $47,000,000 $26,000,000 $23,280,000
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headquarters are in Columbus, Ohio, the district court found the testimony 

unconvincing considering that all four expert witnesses—even Nationwide’s—

described the properties as single-tenant corporate headquarters, and 

Nationwide’s own agreement with the City called for an “expansion of the regional 

headquarters for Nationwide.”

The district court also noted that, despite’s Nationwide’s push to set the 

valuation at the minimum assessment from the parties’ agreement, Nationwide 

never appealed the property tax assessments for 2015, which also landed above

the minimum. The district court further found persuasive Nationwide’s own 

property insurance coverage that set the replacement cost for 1100 Locust at

$148,061,365 and 1200 Locust at $67,804,793—both well above the county 

assessor’s valuations for each property. The district court thus affirmed the Polk 

County Assessor’s original tax valuation of 1100 Locust at $87,050,000 and 

1200 Locust at $44,910,000.

Nationwide appealed, arguing that the Board’s evidence failed to meet the 

requirements set out in Wellmark, Inc. v. Polk County Board of Review, 875 

N.W.2d 667 (Iowa 2016), and, relatedly, that the district court erred in finding 

the Board’s experts more reliable than Nationwide’s experts. After we transferred 

the case, the court of appeals determined that the Board’s experts failed to rely 

on the comparable-sales approach to value the properties as required by statute. 

The Board thus failed, in the court’s view, to support the county assessor’s 

valuation with “competent evidence.” Because the court of appeals found that

Nationwide’s experts, conversely, had properly arrived at their valuations using 
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the comparable-sales approach, the court reversed the decision of the district 

court. Rather than remand, the court set the valuations at the agreed minimums

(from the 2008 agreement) of $78.5 million for 1100 Locust and $36 million for 

1200 Locust.

II.

Iowa law requires that assessors tax property at its “actual value,” which 

refers to its “fair and reasonable market value.” Iowa Code § 441.21(1)(a)–(b)(1). 

Market value, in turn, refers to “the fair and reasonable exchange . . . between a 

willing buyer and a willing seller, neither being under any compulsion to buy or

sell and each being familiar with all the facts relating to the particular property.” 

Id. at § 441.21(1)(b)(1).

The Code establishes the sales approach as the preferred method of 

determining valuation, requiring that “[s]ale prices of the property or comparable 

property in normal transactions reflecting market value, and the probable 

availability or unavailability of persons interested in purchasing the property, 

shall be taken into consideration in arriving at its market value.” Id. We have 

interpreted this to mean “a party cannot move to other-factors valuation unless 

a showing is made that the market value of the property cannot be readily 

established through market transactions.” Wellmark, 875 N.W.2d at 682. Our 

cases have repeatedly recited the sales approach’s favored status. See, e.g.,

Heritage Cablevision v. Bd. of Rev., 457 N.W.2d 594, 597 (Iowa 1990); Bartlett & 

Co. Grain v. Bd. of Rev., 253 N.W.2d 86, 87–88 (Iowa 1977) (en banc).
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Despite the Code’s preference for the sales approach, valuations using 

comparable sales alone are not always appropriate. When market value can’t be 

“readily established” using a sales approach, “the assessor may determine the 

value of the property using the other uniform and recognized appraisal methods.” 

Iowa Code § 441.21(2). These “other” methods include “its productive and 

earning capacity, if any” (in other words, the income approach) and “its cost, 

physical and functional depreciation and obsolescence and replacement cost” (in 

other words, the cost approach), along with “all other factors which would assist 

in determining the fair and reasonable market value of the property.” Id.

The taxpayer bears the initial burden of proving that an assessment is 

incorrect. Id. § 441.21(3)(b)(1). But if the taxpayer presents “competent evidence” 

from two or more disinterested witnesses that the property’s market value is less 

than the assessed value, then the burden of proof swings to the assessor. Id. In 

this case, it’s undisputed that Nationwide presented competent evidence through 

its experts to rebut the presumption of validity, thus shifting the burden to the 

Board to uphold the assessment. See id.; Equitable Life Ins. v. Bd. of Rev., 281 

N.W.2d 821, 824 (Iowa 1979).

Although acknowledging the burden had shifted to the Board, the court of 

appeals found that the district court failed in the initial step of the analysis when 

it determined that the properties’ values could not be readily established using 

the sales approach. The assumption that the Board’s experts did not present 

competent evidence because neither relied on the sales approach misconstrues 
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the question of competent evidence. The real question involves a judgment about 

the persuasive force of the properties tendered by an expert as “comparable.”

In some cases, the lines of force between the assessed and comparable

properties will be too remote to exert any real pull. When that happens—as the 

statute contemplates, and as we held in Wellmark—using other valuation 

methods in the analysis is appropriate. “The statutory preference for evaluations 

based on comparable sales,” after all, “applies only to those situations where the 

value may be readily established by that method alone.” Heritage Cablevision, 

457 N.W.2d at 597.

We review tax protest cases de novo. Soifer v. Floyd Cnty. Bd. of Rev., 759 

N.W.2d 775, 782 (Iowa 2009). Although we give weight to the district court’s 

factual findings, we’re not bound by them. Boekeloo v. Bd. of Rev., 529 N.W.2d 

275, 276 (Iowa 1995). But we are “especially deferential to the court’s assessment 

of the credibility of witnesses.” Wellmark, 875 N.W.2d at 672.

The district court found that the comparable-sales approach could not 

readily establish the properties’ values, and it thus looked to the other 

approaches that the experts presented. In finding the Board’s experts’ opinions 

more reliable, the district court necessarily adopted the Board’s experts’ views 

that the sales approach alone was inadequate to readily establish the market 

value of the two properties. The district court did so with the benefit of having 

heard directly the experts’ testimony to assess the persuasive force of their 

valuation opinions. That all the experts used all three approaches in arriving at 

a valuation could reasonably imply that a property’s market value “could not
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readily be established through the ‘sales prices’ approach alone but had to be 

determined by use of the ‘other factors’ approach.” Equitable Life Ins., 281 

N.W.2d at 825 (emphasis added). Yet the court of appeals determined that the 

Board’s experts “did not present competent evidence of the value of [the 

properties]” because they relied too heavily on factors other than comparable

sales in their analysis. 

The court of appeals, in our view, grafted too rigid a standard onto section 

441.21. The determination that the Board’s experts failed to present competent 

evidence (because neither relied on the sales approach) misconstrues what the 

statute refers to as “competent evidence.” See Iowa Code § 441.21(3)(b)(1). In 

Compiano v. Board of Review, we stated that “the production of competent 

evidence by two disinterested witnesses in tax assessment cases only pertains to 

shifting the burden of proof.” 771 N.W.2d 392, 397 (Iowa 2009). There’s no 

dispute that Nationwide’s two expert witnesses fit the bill and that the burden 

shifted to the Board to uphold the assessments. But the quantum of an expert’s 

reliance on the sales approach as opposed to other factors does not, on its own, 

determine whether a party has produced competent evidence in a case. See 

Wellmark, 875 N.W.2d at 682.

What’s more, simply because an appraiser calculates a valuation using a 

comparable-sales approach does not mean that this approach in fact readily 

establishes a property’s value. We need look no further than our most recent 

appraisal case for proof. In Wellmark, experts for both sides offered valuations 

using a comparable-sales approach to assess Wellmark’s headquarters. Id. at 
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681–82. The experts disagreed, of course, about what properties were truly 

comparable—the taxpayer’s experts used sales from geographic markets similar 

to Des Moines, but multi-tenant office buildings; the board’s experts used sales 

of single-occupant office buildings, but in large metropolitan areas. Id. Yet we

found both side’s comparable-sales-based valuations unconvincing. Id. We 

reiterated that comparable sales are not strictly limited by geographic area, nor 

do they need to be identical to the subject property (only similar). Id. (“[W]hether 

properties were sufficiently similar to be comparable was generally left to the 

sound discretion of the district court.”). Because “[t]he value of the building

simply could not be readily established by a comparable-sales analysis,” we 

considered other factors to establish the property’s value. Id.

In our view, the same consideration of “other factors” is necessary in this 

case. The expert witnesses presented a number of recently sold properties as 

“comparable sales.” But the properties cited in Des Moines, for instance, were 

multi-tenant office buildings with (as one might expect) varying uses by those 

multiple tenants, or were not build-to-suit corporate headquarters. The proposed 

properties that didn’t suffer these incongruent characteristics were in 

substantially dissimilar markets than Des Moines (for instance, suburban 

Chicago, Kansas City, or St. Paul), thus leaving plenty of doubt about how much 

weight to afford the other-market sales prices. Ideally, appraisers would find a 

recent sale in the same geographic region as their subject property of similar 

size, age, condition, and current use. But this is simply not always possible, 

particularly with a built-to-suit corporate headquarters. No expert provided 
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evidence of any sales in the Des Moines area of a large office building to an 

owner-occupant for that occupant’s sole use as a corporate headquarters.

It bears repeating that each expert used all three approaches—income, 

cost, and comparable-sales—in forming a proposed reconciled valuation. 

“Implicit in this evidence”—referring to expert opinions using all three methods 

of valuation—“is an assumption by the parties that market value for the property 

could not readily be established through the ‘sales prices’ approach alone but 

had to be determined by use of the ‘other factors’ approach.” Equitable Life Ins.,

281 N.W.2d at 825; see also Wellmark, 875 N.W.2d at 683 (reciting, with 

approval, cases using the cost approach to value a single-tenant corporate 

headquarters when comparable sales were inadequate). None of the experts in 

this case proposed that the court use only a comparable-sales approach to 

valuing Nationwide’s properties. And because comparable sales alone were 

inadequate, the district court correctly considered “other factors.” Iowa Code 

§ 441.21(2) (requiring that “the actual value shall not be determined by use of 

only one such factor”).

We find no basis to reject the district court’s determination about the 

relative reliability of the expert witness testimony or the court’s reliance on the 

reconciled values incorporating other factors in the analysis, and thus hold that

the Board met its burden to prove the valuation was not excessive. We affirm the 

assessments of 1100 Locust at $87,050,000 and 1200 Locust at $44,910,000.

DECISION OF THE COURT OF APPEALS VACATED; DISTRICT COURT 

JUDGMENT AFFIRMED.
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All justices concur except May, J., who takes no part.